During 2011-2012, the Protein Chemistry Core provided services to investigators in the NCI-CCR as well as other NIH institutes. In addition, the Protein Chemistry Core collaborated with laboratories in the extramural community. The Core performed endoproteolytic digestions on 32-P labeled protein samples and analyzed the resulting peptides by high pressure liquid chomatography, phosphoamino acid analysis and Edman degredation, resulting in the identification of sites of protein phosphorylation. The Core also processed samples for comparative 2D-gel analysis and served as a resource to investigators regarding these techniques.